Inkjet nozzle assembly having resistive element spaced apart from substrate

Abstract

An inkjet nozzle assembly includes a nozzle chamber positioned on a substrate and an actuator for ejecting an ink droplet from a nozzle aperture when a resistive element of the actuator is heated by an electrical current. The resistive element of the actuator is spaced apart from the substrate.

1. An inkjet nozzle assembly comprising:
 a nozzle chamber positioned on a substrate, said nozzle chamber having a nozzle aperture; and 
 an actuator associated with said nozzle chamber for ejecting an ink droplet from said nozzle aperture when a resistive element of said actuator is heated by an electrical current; 
 
       wherein at least part of the resistive element is spaced apart from said substrate, and wherein at least part of an upper surface and a lower surface of said actuator are in contact with ink contained in said nozzle chamber. 
     
     
       2. The inkjet nozzle assembly as claimed in  claim 1 , wherein said substrate is comprised of silicon. 
     
     
       3. The inkjet nozzle assembly as claimed in  claim 1 , wherein said substrate comprises one or more CMOS layers. 
     
     
       4. The inkjet nozzle assembly as claimed in  claim 3 , wherein said one or more CMOS layers comprise a drive transistor for each actuator, each drive transistor providing an energy pulse to a respective resistive element. 
     
     
       5. The inkjet nozzle assembly as claimed in  claim 4 , wherein said one or more CMOS layers comprise control logic for controlling each drive transistor. 
     
     
       6. The inkjet nozzle assembly as claimed in  claim 3 , wherein said one or more CMOS layers are passivated with a passivation layer, and each nozzle chamber is disposed on said passivation layer. 
     
     
       7. The inkjet nozzle assembly as claimed in  claim 6 , wherein said nozzle nozzle chamber is positioned to overlie at least one of a drive transistor and control logic contained in said one or more CMOS layers. 
     
     
       8. The inkjet nozzle assembly as claimed in  claim 6 , wherein said actuator is electrically connected to an uppermost CMOS layer via one or more vias etched through said passivation layer. 
     
     
       9. The inkjet nozzle assembly as claimed in  claim 1 , wherein said nozzle chamber contains at least part of said actuator. 
     
     
       10. The inkjet nozzle assembly as claimed in  claim 1 , wherein said resistive element of said actuator is comprised of titanium nitride. 
     
     
       11. The inkjet nozzle assembly a  claim 1 , wherein said actuator is moveable relative to said substrate. 
     
     
       12. An inkjet printhead comprising a plurality of inkjet nozzle assemblies according to  claim 1 .